The disclosure relates to an image forming apparatus, such as a laser printer, and a process cartridge for use in the image forming apparatus.
Conventionally, a process cartridge for use in image forming apparatuses, such as laser printers, includes a charger, a developing roller, and a transfer roller that are disposed around a photosensitive drum. In accordance with the rotation of the photosensitive drum, its surface is uniformly charged by the charger, and then selectively exposed to a laser beam. This process partially removes electrical charges from the surface of the photosensitive drum to form an electrostatic latent image on the surface of the photosensitive drum. The electrostatic latent image on the surface of the photosensitive drum is developed into a toner image as toner is supplied from the developing roller when the electrostatic latent image is brought into contact with the developing roller. The toner image carried on the surface of the photosensitive drum faces the transfer roller, and is transferred to a sheet passing between the photosensitive drum and the transfer roller.
A known process cartridge is provided with a brush, on the downstream side of the transfer roller with respect to the rotating direction of the photosensitive drum for removing foreign materials such as the paper fibers or powders attached to the surface of the photosensitive drum after the toner image has been transferred on the sheet. The brush is disposed so as to slide on the surface of the photosensitive drum. In accordance with the rotation of the photosensitive drum, foreign materials on the surface of the photosensitive drum are physically caught by the brush and electrically attracted by the application of cleaning bias.
For example, Japanese Laid-Open Utility Model Publication No. 61-76451 discloses a conductive brush for charging a surface of a photosensitive member, attached to a base. An end of the base is held by a substantially U-shaped supporting member to make the brush contact the surface of the photosensitive member.